Becky and tommy are asked to solve −4x − 25 = 8x + 15. identify where one of them made an error. becky tommy −4x − 25 = 8x + 15 −4x − 25 − 8x = 8x + 15 − 8x −12x − 25 = 15 −12x − 25 + 25 = 15 + 25 −12x = 40 negative 12x over 40 equals 40 over 40 x equals negative three-tenths −4x − 25 = 8x + 15 −4x − 25 + 4x = 8x + 15 + 4x −25 = 12x + 15 −25 − 15 = 12x + 15 − 15 −40 = 12x negative 40 over 12 equals 12x over 12 x equals negative ten-thirds